Bijou resistors specs - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 26th May 2015, 10:08 PM   #1
weber30 is offline weber30  United States
diyAudio Member
 
Join Date: May 2015
Location: Concord, CA
Default Bijou resistors specs

I looked at the parts for the Bijou amp on

https://www.cavalliaudio.com/diy/bij...?page=ampparts

and was wondering whether the cheaper resistors with around 100ppm (Temperature Coefficient) will do or if they should be 10ppm or at least 50ppm ? Does it really matter with regards to sound/reliability ? Thanks.
  Reply With Quote
Old 27th May 2015, 12:36 AM   #2
diyAudio Member
 
astouffer's Avatar
 
Join Date: Jun 2004
Location: Pittsburgh, crumbling wasteland
It won't make much difference. You only run into problems in places like opamp feedback loops where a slight change will really show.
  Reply With Quote
Old 27th May 2015, 01:39 AM   #3
diyAudio Member
 
HollowState's Avatar
 
Join Date: Aug 2006
Location: Taxland, New Jersey
For this circuit 100 ppm or even more is not a problem. And for the most part 1% is not necessary either. Personally I never liked or used ⅛ watt resistors. They're too damn small and hard to work with, meaning fragile. ¼ watt is the smallest I use. And metal resistors don't like overloads. But that's another whole discussion.
__________________
"I regard the brain as a computer which will stop working when it's components fail. There is no heaven or afterlife for broken down computers. That is a fairy story for people afraid of the dark." ~Stephen Hawking
  Reply With Quote
Old 27th May 2015, 08:22 AM   #4
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
Specifying 1/8W resistors for a valve design is daft. At the first DC fault half your resistors go up in smoke; then how do you do fault tracing? 1/4W minimum, but 1/2W would be better.

Temperature coefficient is irrelevant. Almost all modern resistors are much better than those which were routinely used in the valve era.
  Reply With Quote
Old 27th May 2015, 05:12 PM   #5
weber30 is offline weber30  United States
diyAudio Member
 
Join Date: May 2015
Location: Concord, CA
Default Bijou parts (capacitors)

I'm going through the parts list for the Bijou and it (among others) lists the following two capacitors:

Metalized Polyester/Polypropylene Film 100n 400V
Metalized Polyester/Polypropylene Film 1u 250V

I looked at mouser.com and seem to have difficulty finding the right one (sorry, newbie issue). Anybody got a link?

Does the 400V or 250V refer to AC or DC voltage?

Thanks for the help.
  Reply With Quote
Old 27th May 2015, 05:26 PM   #6
rayma is online now rayma  United States
diyAudio Member
 
Join Date: Apr 2011
Location: Upper midwest
Quote:
Originally Posted by weber30 View Post
Does the 400V or 250V refer to AC or DC voltage?
The marked voltage is always DC (or peak) unless specifically marked AC.
The outer foil is often marked with a line.

Last edited by rayma; 27th May 2015 at 05:41 PM.
  Reply With Quote
Old 27th May 2015, 05:35 PM   #7
SY is offline SY  United States
diyAudio Moderator
 
SY's Avatar
 
Join Date: Oct 2002
Location: Chicagoland
Blog Entries: 1
Film Capacitors | Mouser

Film Capacitors | Mouser

There's an embarrassingly large selection.
__________________
“The short explanation is always dull. It generally includes the word ‘just.’ The explanation only becomes beautiful when you immerse yourself in every nuance.”
  Reply With Quote
Old 28th May 2015, 04:21 PM   #8
weber30 is offline weber30  United States
diyAudio Member
 
Join Date: May 2015
Location: Concord, CA
Quote:
Originally Posted by DF96 View Post
Specifying 1/8W resistors for a valve design is daft. At the first DC fault half your resistors go up in smoke; then how do you do fault tracing? 1/4W minimum, but 1/2W would be better.

Temperature coefficient is irrelevant. Almost all modern resistors are much better than those which were routinely used in the valve era.
I guess you got a good point there. Why safe on a few cents here...
  Reply With Quote
Old 28th May 2015, 04:27 PM   #9
weber30 is offline weber30  United States
diyAudio Member
 
Join Date: May 2015
Location: Concord, CA
Default Bijou transformer

I am still going through the list of parts for the Bijou amp and started looking at the transformer. It lists the Hammond 270 DAX (117 VAC ; 6.3V at 3.5A) as the recommendation. I read some places, though, that EdCor got some cheaper ones. Anybody know their equivalent (model number) and maybe reasons why using one of those might be a bad idea?

I was also wondering if there is any sound improvement in getting two and running each channel separately (as a mono block, so to say) ?
  Reply With Quote
Old 28th May 2015, 05:34 PM   #10
diyAudio Member
 
Join Date: Dec 2010
Location: Amesbury, MA
Edcor makes good transformers for the money. The only problem is they make them when you place your order so for me it is usually about 8 weeks wait time.

I have noticed that you have multiple threads for just this one amplifier. It might be less confusing to people if you had just one thread dedicated to this amplifier. Maybe mods can tidy it up into one thread? Anyway I have had good luck with Edcor transformers.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bijou schematics question (PINs) weber30 Tubes / Valves 2 26th May 2015 10:11 PM
Cavalli Audio Bijou Completed internals with transformer. jwags818 Swap Meet 0 9th March 2015 07:16 PM
Cavalli Bijou Headphone Amp completed PCB's and Hammond Daz Transformer joefish Swap Meet 3 7th May 2013 05:53 PM
FS: Bijou Headphone Amp huskydawg9 Swap Meet 0 8th May 2010 05:23 PM
Sugden Bijou CD Master TB3 Digital Source 0 15th February 2004 11:39 PM


New To Site? Need Help?

All times are GMT. The time now is 03:24 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2015 DragonByte Technologies Ltd.
Copyright ©1999-2015 diyAudio

Content Relevant URLs by vBSEO 3.3.2